Since there are enough OHC threads on this site already with pictures, I'll just report in that my trip to the salvage yard on Saturday was soggy but successful. I took a piece of paper and made a rub off tracing of an Exploder mounting holes. Came home and relocated the mounting bracket about 1/2" down from the nested location.
Lengthened the slots and the center mounting hole. Reinstalled the bracket and it snapped right in with a lot of upward pressure. The screws pulled the back end up nicely to the headliner and there are no visible gaps. Glad I did not trim any more out of the back end.
Anyway, I have completed the OHC mod, the Taurus Dome Light mod, and the pre 2003 cargo box CHMSL mod. In addition I ordered and installed a new set of factory ebony floor mats which compliment the black and gray color scheme of my FX4 interior.
I took a couple of pictures of the Exploder mounting locations. I can make a copy of the mounting location template and place it in a PDF format. Was thinking that these might be good items to create a "sticky" for so if people want a copy of the template they can print it off and save themselves some frustration.
Anyway, thanks to all who offered suggestions and thanks to soccerjohn and sad savant for their guidance and assistance. Time to get back to building a hot rod.